I'm having exactly the same problem. I'm getting 403 Forbidden whenever I try to save any updates.
I tried everything on www.joomfreak.com/forum/categories/jooml...w/403-forbidden.html
with no luck.
I'm about to chuck it out and use another module instead unless someone can sort this crap out.

Well.. you may try this (I resolved)
file .htaccess (if there ins no, made it) insert (temporary) this code:
<IfModule mod_security.c>
SecFilterEngine Off
SecFilterScanPOST Off
</IfModule>

I'm not sure what this "(if there ins no, made it) " means sorry. Less tech more communicate.

Sorry to bug you again .. my whole site seems to be stuffed now. I get 403 Forbidden on all pages.

OK .. I just turned "URL rewriting" off in Joomla and the site is working OK.
However, it was working quite fine with "URL rewriting" up until I installed and tried to get your product working.
I have since moved on to another product which works out of the box without having to reconfigure the application. I'll stick with that I think.